PubMed Health⌕ Search

Biomedical subjects

C Peschle

Publications and source records attributed to C Peschle.

At least 19 recordsLinked to original sources
PubMed1992

Production of hemolymphopoietic cytokines (IL-6, IL-8, colony-stimulating factors) by normal human astrocytes in response to IL-1 beta and tumor necrosis factor-alpha.

Astrocyte-enriched populations were established from human embryonic brain analyzed for their ability to synthesize cytokines potentially relevant for mechanisms of inflammation and immunity in the brain. Unstimulated astrocytes did not secrete significant IL-6, IL-8, macrophage CSF (M-CSF), granulocyte-macrophage CSF (GM-CSF), or granulocyte-CSF (G-CSF), as determined by specific ELISA and/or bioassay. With the exception of M-CSF mRNA, transcripts for the above factors were not detected in unstimulated astrocytes. On exposure of human astrocytes to IL-1 beta, high levels of IL-6, IL-8, M-CSF, G-CSF, and GM-CSF mRNAs were detected; moreover, active secretion of all the above cytokines was demonstrated. TNF-alpha was also able to stimulate IL-6, IL-8, M-CSF, GM-CSF, and G-CSF synthesis and secretion, but was generally less potent than IL-1 beta. No IL-3 mRNA or protein was detected in unstimulated or cytokine-treated astrocytes. IL-1 alpha and IL-1 beta mRNAs and proteins were not detected in unstimulated astrocytes, but were present in very small amounts after stimulation with TNF-alpha/IL-1 beta. No IL-6, M-CSF, GM-CSF, G-CSF, or IL-8 were induced by IL-1 beta or TNF-alpha in early primary cultures, which mainly contain undifferentiated neuronal/glial progenitor cells. These studies demonstrate for the first time the production of multiple cytokines by normal human astrocytes stimulated in culture by IL-1 beta and TNF-alpha. The capacity of human astrocytes to synthesize and release cytokines active on hemolymphopoietic cells supports the concept that these cells play an important role in the regulation of inflammatory and immune responses in a variety of brain pathologies.

Astrocytes↗
PubMed1992

Developmental switching of messenger RNA expression from the human alpha-globin cluster: fetal/adult pattern of theta-globin gene expression.

The alpha-globin gene cluster contains four functional globin genes, zeta, alpha 2, alpha 1, and theta. The developmental regulation of the embryonic zeta and fetal/adult alpha 2- and alpha 1-globin genes is well characterized at the level of protein synthesis. The developmental pattern of the theta-globin gene is not well characterized due to the inability to detect its encoded protein. Direct analysis of the globin switching at the steady-state messenger RNA (mRNA) level has been hampered by the difficulty in obtaining quantities of embryonic and early fetal mRNA sufficient for analysis. We analyzed the relative levels of the steady-state zeta-, alpha-, and theta-globin mRNAs in yolk sac in 5-, 6-, 7-, and 8-week postconception embryonic liver, and in cord and adult blood reticulocytes. We show that the switch in the alpha-globin gene cluster from the embryonic to fetal/adult pattern of expression begins at 5 to 6 weeks of gestation. Both the theta- and alpha-globin genes show similar patterns of developmental control that are reciprocal to zeta. alpha-globin RNA is barely detectable or undetectable at 5 weeks, and increases in the 6- to 8-week period, while theta-globin mRNA shows a parallel increase at 5 to 8 weeks postconception and is expressed in cord blood and adult reticulocytes. These data show that the theta-globin gene represents a fetal/adult gene, albeit expressed at a low level.

Adult↗
PubMed1992

A human HOX4B regulatory element provides head-specific expression in Drosophila embryos.

Like other homeobox genes of the Antennapedia and bithorax complexes (collectively called the HOM complex), the Drosophila Deformed (Dfd) gene has structural homologues in the Hox/HOX complexes of mouse and humans, one of which is human HOX4B (refs 3, 4). Previous experiments indicated that HOX4B protein can specifically activate the expression of the endogenous Dfd transcription unit in Drosophila embryos and larvae. We therefore asked whether HOX4B cis-regulatory elements could mimic the function of a Dfd autoregulatory element in Drosophila embryos. Here we show that a HOX4B upstream element can surprisingly provide expression in a posterior head segment of Drosophila. One possible mechanism for the axial position-specificity of the human element may involve the conservation of a Dfd-specific autoregulatory circuit in both arthropod and chordate lineages. This possibility is supported by the finding that a Drosophila Dfd autoregulatory element supplies spatially localized expression in the hindbrain of mouse embryos.

Animals↗
PubMed1992

Expression of selected human HOX-2 genes in B/T acute lymphoid leukemia and interleukin-2/interleukin-1 beta-stimulated natural killer lymphocytes.

Although the key role of human homeobox (HOX) genes in development is well established, their function in adult cells is still under scrutiny. We have analyzed, in normal adult blood cell subpopulations, acute lymphoid leukemia (ALL) cells lines, and primary blasts, the RNA expression of all HOX-2 cluster genes (5'-2.5, 2.4, 2.3, 2.2, 2.1, 2.6, 2.7, 2.8, 2.9, 3') and nine genes in the HOX-1, -3, and -4 cluster by Northern blotting, RNAse protection, and/or reverse transcriptase polymerase chain reaction (RT-PCR). The analyzed HOX-1, -3, and -4 genes were never expressed in all tested cell populations. Natural killer (NK) cells activated in interleukin-2 (IL-2)/IL-1 beta-treated cultures exhibit a gradually increasing, abundant expression of three HOX-2 genes (2.2, 2.6, 2.8), while three other genes (2.3, 2.1, 2.7) are expressed at a lower level at late culture times. However, no HOX-2 gene is expressed in quiescent lymphocytes (NK, B and T [T-cell receptor (TCR) alpha/beta, gamma/delta lymphocytes, thymocytes] cells), granulocytes, and monocytes. In B- and T-ALL cell lines, HOX-2 genes are expressed according to different patterns: (1) widespread transcription (seven of nine genes, including 2.3 and 2.6) in the Peer line bearing the TCR gamma/delta; (2) expression of 2.5, 2.2, and 2.6 in the SEZ 627 line, which derives from an HTLV-1+ T-helper leukemia; (3) transcription of 2.3 and 2.6 in both the T-ALL CEM line and four B-ALL lines (interestingly, CALLA- B-ALL lines are constantly 2.3/2.6 RNA+); (4) no HOX-2 gene expression was detected in one T- and two B-ALL lines. Primary blasts from five T- and five pre-B-ALL showed selective expression of one or more HOX-2 genes, namely 2.5, 2.2, 2.6, and 2.7. Our data are compatible with the hypothesis that selected HOX-2 genes play a role in the IL-2/IL-1 beta-induced activation and/or proliferation of normal NK lymphocytes and possibly in the oncogenetic process of some T- and B-ALL.

Base Sequence↗
PubMed1992

Post-transcriptional regulation of transferrin receptor mRNA by IFN gamma.

IFN gamma inhibits the rise in transferrin receptor mRNA level which is normally observed when stationary WISH cells are stimulated to proliferate. This effect is not attributable to a change in the transcription rate of the transferrin receptor gene or in the cytoplasmic stability of the mRNA. The IFN gamma-induced reduction of the transferrin receptor mRNA content is already present at the nuclear level to an extent comparable to that observed in whole cells. Thus, IFN gamma does not impair the passage of this mRNA from the nuclear to the cytoplasmic compartment but probably interferes with a nuclear post-transcriptional event during the processing of the immature transferrin receptor mRNA. Two different levels of regulation of transferrin receptor mRNA have been previously reported. Iron modulates the cytoplasmic stability of this mRNA through the binding of a specific cytoplasmic factor, whereas cell growth variation influences the transcription of this gene. Our results suggest the existence of another mechanism of regulation for transferrin receptor gene expression not so far considered. Furthermore, the distinction between the mechanism of regulation exerted by IFN gamma and that exerted by cell proliferation on transferrin receptor gene expression suggests that, in WISH cells, the IFN-induced transferrin receptor decay is not a consequence of cell growth arrest but rather one of the causes of the antiproliferative effect of IFN through iron deprivation.

Blotting, Northern↗
PubMed1992

Transferrin receptor mediates uptake and presentation of hepatitis B envelope antigen by T lymphocytes.

Human activated T lymphocytes expressing class II molecules are able to present only complex antigens that bind to their own surface receptors, and thus can be captured, internalized, and processed through the class II major histocompatibility complex processing pathway. We have used the antigen-presenting T cell system to identify the viral receptor used by hepatitis B virus (HBV) to enter cells, as well as the sequence of HB envelope antigen (HBenvAg) involved in this interaction. Results show that both CD4+ and CD8+ T clones can process and present HBenvAg to class II-restricted cytotoxic T lymphocytes and that the CD71 transferrin receptor (TfR) is involved in efficient HBenvAg uptake by T cells. Moreover, we provide evidence that the HBenvAg sequence interacting with the T cell surface is contained within the pre-S2 region. Since TfR is also expressed on hepatocytes, it might represent a portal of cellular entry for HBV infection. This system of antigen presentation by T cells may serve as a model to study both lymphocyte receptors used by lymphocytotropic viruses and viral proteins critical to bind them.

Amino Acid Sequence↗
PubMed1992

Developmental switch in the relative expression of the alpha 1- and alpha 2-globin genes in humans and in transgenic mice.

Human alpha-globin is encoded by two adjacent genes, alpha 2 and alpha 1. Despite their remarkable level of structural identity, the more 5' (alpha 2) gene is the major alpha-globin locus in the normal adult, expressed at 2.6-fold higher levels than the adjacent and more 3' (alpha 1) globin gene. In light of the well-characterized pattern of gene activation in the human alpha- and beta-globin gene clusters during development, we considered the possibility that the relative expression of these two alpha-globin loci might be developmentally controlled. Analysis of human embryonic and early fetal erythroid RNA samples confirmed this possibility; levels of mRNA encoded by the two alpha-globin loci are equal in the embryo and subsequently shift to dominant expression of the alpha 2-globin locus at week 8 in utero. In transgenic mice carrying the entire human alpha-globin cluster (except for the theta gene) we show the same shift from equal expression of the alpha 1- and alpha 2-globin loci at the embryonic stage to predominance of the alpha 2-globin locus in the adult. These data demonstrate a switch in the expression of the two adjacent alpha-globin genes during the embryonic-to-fetal switch in erythroid development and provide an experimental system for its further characterization.

Age Factors↗
PubMed1992

Transforming growth factor beta (TGF-beta) inhibits expression of fibrinogen and factor VII in a hepatoma cell line.

We have investigated the effect(s) of transforming growth factor (TGF)-beta 1 and interleukin (IL)-6 on the expression of fibrinogen and blood coagulation factors VII, IX, X mRNAs in a hepatoma cell line (Hep 3B). The results indicate that TGF-beta induces a decrease of the basal level of fibrinogen and factor VII mRNAs, but does not affect factor X expression. Furthermore, TGF-beta efficiently antagonizes the IL-6 induction of fibrinogen mRNA at late (12-48 h) but not early (6 h) times: this effect is apparently mediated by posttranscriptional mechanism(s). These findings, together with previously reported data on the inhibitory effect of TGF-beta on acute phase genes (e.g., ApoA1 and albumin), suggest a role for TGF-beta in the regulation of liver genes expression. The early stimulatory and late inhibitory effect exerted by IL-6 and TGF-beta respectively on fibrinogen mRNA level may play a role in the regulatory mechanism(s) of clot formation in a variety of conditions.

Carcinoma, Hepatocellular↗
PubMed1992

Developmental appearance, antigenic profile, and proliferation of glial cells of the human embryonic spinal cord: an immunocytochemical study using dissociated cultured cells.

We have investigated the time of appearance of the earliest differentiating glial cell types of human spinal cord using a panel of antigenic markers to identify them in cultures from 6- to 9-week-old human embryos. Immunolabeling performed at 14 h in vitro with the O4 mAb, an early oligodendrocyte marker, showed the presence of oligodendrocytes during the 7th week of age. At 8 weeks only a few of the O4+ cells expressed galactocerebroside (GalC), a marker of more differentiated oligodendrocytes. All the O4+ and GalC+ cells were vimentin+ and some of the GalC+ cells were A2B5+, GD3+ and SSEA-1+. During the first week in vitro many of the O4+ cells exhibiting a more immature, bi- or tri-polar morphology incorporated [3H]thymidine into their nuclei. Cells expressing the astrocyte-specific marker GFAP could be first observed at 8 weeks; almost all of these GFAP+ cells, which should correspond to radial glia on the basis of the current literature, were vimentin+, A2B5+, GD3+, and SSEA-1+. At 2 days in vitro incorporation of [3H]thymidine could be shown in a small fraction of these cells. The finding that radial glia and oligodendrocytes expressed similar antigenic features and the additional observation that a small, but consistent fraction of the cells were simultaneously labeled by O4 and anti-GFAP antibodies support the hypothesis that, in the human spinal cord, radial glial cells can give rise to both oligodendrocytes and astrocytes; in this respect, radial glial cells may be similar to the A2B5+, GD3+, vimentin+ bipotential glial progenitors previously identified in cultures from developing rat CNS, which also express A2B5, GD3, and vimentin.

Antibodies↗
PubMed1992

Astrocyte cultures from human embryonic brain: characterization and modulation of surface molecules by inflammatory cytokines.

Astrocyte-enriched cultures were established upon passaging of primary cultures from the myelencephalon and mesencephalon of 7-9-week-old human embryos. Immunocytochemical analysis showed that third-fourth passage cultures were composed of a highly enriched population of proliferating, epithelioid cells, up to 90% of which expressed glial fibrillary acidic protein (GFAP); no macrophages and very few fibroblasts (less than 2%) were present. GFAP expression and proliferation declined upon further culturing in serum-containing medium but could be transiently reinduced by growing the cells in a serum-free chemically defined medium. Large numbers of GFAP+ astrocytes were obtained from each embryo and could be stored frozen and recultured. Using flow cytometric analysis, human astrocyte cultures were examined for basal and cytokine [interferon-gamma (IFN-gamma), interleukin-1 beta (IL-1 beta), and tumor necrosis factor-alpha (TNF-alpha)]-induced expression of molecules that may be involved in astrocyte-T-lymphocyte interactions. Cultured human astrocytes spontaneously expressed major histocompatibility complex (MHC) class I antigens and variable levels of MHC class II; MHC class I levels were increased upon IFN-gamma and TNF-alpha treatment, whereas MHC class II antigens were induced on most of the astrocytes by IFN-gamma. Among the molecules involved in antigen-independent interactions between T lymphocytes and target cells, lymphocyte function-associated molecule-3 (LFA-3) was spontaneously expressed by most cultured human astrocytes, whereas intercellular adhesion molecule-1 (ICAM-1) was present at variable levels in non-stimulated astrocytes and was greatly induced by IFN-gamma, TNF-alpha, and IL-1 beta. In this study we also show that the above cytokines upregulate astroglial expression of adhesion molecules of the integrin family (VLA-1, VLA-2, and VLA-6) that may be involved in astrocyte-extracellular matrix interaction and play a role in the astrocyte reactive changes occurring at sites of brain injury and inflammation. The human astrocyte cultures developed here represent a useful in vitro model to further investigate mechanisms involved in bidirectional communication between central glia and cells of the immune system.

Astrocytes↗
PubMed1992

Effects of a preformed extracellular matrix on long-term serum-free bone marrow culture.

The extracellular matrix (ECM) produced by the stromal layer plays a key role in the regulation of commitment and differentiation of hematopoietic cells. Long-term bone marrow culture (LTBMC) allows analysis of the stromal microenvironment. Recently, serum-free LTBMC has been described, but the formation of a classical adherent layer was never observed under these conditions. We have evaluated the effect(s) of a chemically well defined ECM on serum-free and serum-dependent LTBMC. In serum-dependent cultures ECM did not induce a significant increase of hematopoiesis. In serum-free conditions, a marked improvement of hematopoiesis was observed, both in terms of CFU-GM and BFU-E yield and in duration of cultures. A confluent stromal layer was observed only in the presence of ECM. The present results indicate that the addition of ECM to serum-free cultures provides a standardized culture condition, while improving progenitor cell recovery and allowing formation of a confluent stromal layer. Moreover, ECM+LTBMC may provide a model to study the effect(s) of adhesive proteins and hematopoietic growth factors normally present in serum.

Blood↗
PubMed1992

Extrachromosomal human immunodeficiency virus type 1 DNA forms in fresh peripheral blood lymphocytes and in two interleukin-2-independent T cell lines derived from peripheral blood lymphocytes of an asymptomatic seropositive subject.

Two immature T cell lines (FT1 and FT4) were established after in vitro cloning of peripheral blood lymphocytes (PBLs) from an asymptomatic human immunodeficiency virus type 1 (HIV-1) seropositive, human T cell-lymphotropic virus type 1 seronegative homosexual subject. Although derived from a limiting dilution cell cloning assay, these cell lines were not recloned for this study. Their growth was independent of exogenous interleukin-2. Both cell lines were able to form colonies when cloned in agar, but failed to form solid tumours when injected into nude mice. FT lines belong to the very immature T cell lineage as they exhibit rearranged TCR genes but no expression of T cell membrane antigens, including CD2, CD3, CD4, CD6, CD7 and CD8. They also contain an HIV-1 genome that was detected only in an extra-chromosomal DNA form, even after several passages in vitro. The presence of unintegrated viral DNA was also detected by polymerase chain reaction analysis in the same sample of fresh uncultured PBLs. Furthermore, despite the absence of CD4 expression, both T cell lines were susceptible to CD4-independent HIV-1 superinfection (lack of superinfection inhibition in the presence of OKT4A monoclonal antibodies).

Adult↗
PubMed1992

PCR analysis of HIV-1 sequences and differential immunological features in seronegative and seropositive haemophiliacs.

We have compared the immunological features of two matched groups of seronegative and seropositive haemophilia A individuals. Both groups were exposed from 1981 to 1985 to comparable amounts and batches of FVIII concentrates not subjected to virus inactivation procedures, and had therefore a 100% probability of receiving HIV-contaminated material. The presence of proviral HIV-1 sequences was evaluated by PCR in the DNA from peripheral blood lymphocytes and/or monocytes. After hybridization with specific probes, DNA from all seropositive haemophiliacs revealed HIV sequences; no HIV sequences were observed from the DNA of seronegative patients, even after two rounds of amplification, thus suggesting that these patients were not affected by a latent HIV infection. Seronegative/PCR- and seropositive/PCR+ patients showed a normal and reduced number of CD4+ lymphocytes, and a slight and marked increase of CD8+ cells respectively. Activated T cells expressing the HLA-DR antigen were elevated in both groups. Interestingly, a significant reduction of circulating CD56+/CD3- NK lymphocytes was observed only in seropositive haemophiliacs, whereas NK lymphocytes with CD56+/CD3+ phenotype were within normal levels in both groups. In seropositive patients no correlation was found between the number of CD4+ and CD56+/CD3- lymphocytes. The marked reduction of CD56+/CD3- lymphocytes observed in seropositive haemophiliacs in addition to the CD4+ cell depletion may represent a key pathogenetic factor which facilitates the onset and/or the progression of HIV-1 infection in haemophiliacs, and is related to the capacity of HIV to infect NK cells.

Antigens, CD↗
PubMed1992

Cellular and molecular studies on the early stages of human hematopoietic differentiation in culture of pure progenitors.

Methodology has been developed that enables virtually complete purification and recovery of early hematopoietic progenitors from human adult blood, a minority of which is multipotent and endowed with self-renewal capacities, i.e., exhibits stem cell properties. This report briefly reviews: (i) the key steps involved in the progenitor purification and assay procedure; (ii) the characterization of "pure" progenitors at the level of membrane antigen pattern and response to HGFs; (iii) the development of a liquid suspension culture for the pure progenitors, which allows synchronized and selective erythroid or GM differentiation, and hence may be utilized for the analysis of molecular mechanisms underlying early and late stages of hematopoiesis; (iv) the study of the expression and modulation of HGFRs expressed on progenitors.

Cell Differentiation↗
PubMed1992

C-MYB activation and the pathogenesis of ovarian cancer.

We have detected the expression of the MYB proto-oncogene in ovarian cancer. This oncogene was thought to be expressed in a tissue-specific manner in cells of hematopoietic lineage. Total RNA from three established cell lines and four human primary ovary cancers was examined by Northern and Southern blot, RNAse protection, in situ hybridization and cytogenetic analysis. A 3.8 kb RNA transcript was present in one human primary cell culture which is the same size as that found in the immature myeloid HL60 cell line. No expression was detected in normal ovary tissue. Southern blot analysis of DNA from five ovarian tumors indicated that this gene is not rearranged. Chromosomal analysis of three samples show many abnormalities in two cases and a normal karyotype in another one. The presence of MYB transcript in ovarian cancer suggests that MYB may play a specific role in the pathogenesis of this disease.

Blotting, Northern↗
PubMed1991

Differential regulation of iron regulatory element-binding protein(s) in cell extracts of activated lymphocytes versus monocytes-macrophages.

The intracellular iron level exerts a negative feedback on transferrin receptor (TfR) expression in cells requiring iron for their proliferation, in contrast to the positive feedback observed in monocytes-macrophages. It has been suggested recently that modulation of TfR and ferritin synthesis by iron is mediated through a cytoplasmic protein(s) (iron regulatory element-binding protein(s) (IRE-BP)), which interacts with ferritin and TfR mRNA at the level of hairpin structures (IRE), thus leading to inhibition of transferrin mRNA degradation and repression of ferritin mRNA translation. In the present study we have evaluated in parallel the level of TfR expression, ferritin, and IRE-BP in cultures of: (i) circulating human lymphocytes stimulated to proliferate by phytohemagglutinin (PHA) and (ii) circulating human monocytes maturing in vitro to macrophages. The cells were grown in either standard or iron-supplemented culture. TfR and ferritin expression was evaluated at both the protein and mRNA level. IRE-BP activity was measured by gel retardation assay in the absence or presence of beta-mercaptoethanol (spontaneous or total IRE-BP activity, respectively). Spontaneous IRE-BP activity, already present at low level in quiescent T lymphocytes, shows a gradual and marked increase in PHA-stimulated T cells from day 1 of culture onward. This increase is directly and strictly correlated with the initiation and gradual rise of TfR expression, which is in turn associated with a decrease of ferritin content. Both the rise of TfR and spontaneous IRE-BP activity are completely inhibited in iron-supplemented T cell cultures. In contrast, the total IRE-BP level is similar in both quiescent and PHA-stimulated lymphocytes, grown in cultures supplemented or not with iron salts. Monocytes maturing in vitro to macrophages show a sharp increase of spontaneous and, to a lesser extent, total IRE-BP; the addition of iron moderately stimulates the spontaneous IRE-BP activity but not the total one. Here again, the rise of spontaneous IRE-BP from very low to high activity is strictly related to the parallel increase of TfR expression and, suprisingly, also with a very pronounced rise of ferritin expression observed at both the mRNA and protein level. It is noteworthy the effect of beta-mercaptoethanol is cell specific, i.e. the ratio of total versus spontaneous IRE-BP activity is different in activated lymphocytes and maturing monocytes.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

Two-step differentiation of AML-193 leukemic line: terminal maturation is induced by positive interaction of retinoic acid with granulocyte colony-stimulating factor (CSF) and vitamin D3 with monocyte CSF.

The human AML-193 cell line requires exogenous granulocyte-monocyte colony-stimulating factor (GM-CSF) or interleukin-3 (IL-3) for growth in liquid or semisolid medium. However, these CSFs do not stimulate the differentiation of the cell line. We show that addition of all-trans retinoic acid (RA) or 1,25 dihydroxyvitamin D3 (D3) induces AML-193 cells to differentiate into the granulocytic or monocytic lineage, respectively. On the other hand, addition of either G- or M-CSF alone exerts virtually no differentiative effect. Terminal granulocytic or monocytic differentiation was observed when AML-193 cells were treated with RA and G-CSF, or D3 and M-CSF, respectively, as evaluated by cell morphology, analysis of surface antigens, and phagocytic functions. These positive interactions indicate that the differentiating activity of G- and M-CSF on leukemic cells may be unmasked by preliminary treatment with RA and D3, respectively, ie, the physiologic inducers override the leukemic differentiation blockade and CFSs exert their differentiative activity on the unblocked leukemic cells. These preliminary observations on a single cell line may pave the way for the designing of clinical protocols combining physiologic inducer(s) and hematopoietic growth factor(s) in the treatment of acute leukemia.

Antibodies, Monoclonal↗